Heating and cooling device and method

ABSTRACT

A method and apparatus for dividing a gas into two parts: a first part which is cooler and a second part which is warmer than the original gas. The apparatus includes a molecular filter for selectively passing molecules of the original gas that have a statistical distribution of velocities which is different than the statistical distribution of molecular velocities of the original gas, and a gas pump for establishing a pressure differential across the filter. The molecules which are passed through the filter will therefore exhibit a different temperature than the molecules which are not passed through.

United States Patent 11 1 Milde, Jr.

1451 Dec. 11, 1973 HEATING AND COOLING DEVICE AND METHOD PrimaryExaminerCharles Sukalo [76] Inventor: Karl F. Milde, Jr., 29 Kings Ct.,

Brooklyn, N.Y. 10514 [57] ABSTRACT [22] Filed: June 9, 1971 A method andapparatus for dividing a gas into two [21] Appl 151398 parts: a firstpart which is cooler and a second part Related [1.8. Application Datawhich is warmer than the original gas. The apparatus 3 Continuatiomimpanf Sen No. 794,645, Jam 28 includes a molecular filter for selectivelypassing mol- 19 9 abandone ecules of the original gas that have astatistical distribution of velocities which is different than thestatisti- [52] US. Cl 165/54, 165/61, 55/16 cal distribution f moleculare ocities of the original [51] Int. Cl. F24h 3/02 g and a g p p for a isng a p ssure differ- [58] Field of Search 55/16, 17; 165/14, entialacross h filt r- The molecules which are 165/61, 54, 49 passed throughthe filter will therefore exhibit a differ- A ent temperature than themolecules which are not References Cited passed through.

UNITED STATES PATENTS 2,966,235 12/1960 Kammerrneyer 55 16 7 Clams 8D'awmg 7/ \urununununusuhununvnwnut h I l i E e 30 s E 25 i 5 Z7- Q a he e v i i 26 e m n mum 1 m5 SIHIIBFZ nl'n.

FIG. 3

R w E YD EL M I E L R A K l, HEATING AND COOLING DEVICE ANDMETIIOD CROSSREFERENCE TO RELATED APPLICATION This application is acontinuation-in-part'ofapplica tion Ser. No. 794,645 fileddan. 28, 1969by Karl F. Milde, Jr. and now abandoned.

BACKGROUND OF THE INVENTION The present invention relates to the heatingand cooling art; specifically, to the art of heating and cooling a roomor rooms intended for human habitation.

All the various techniques which have been used in the art for/heatingor cooling a room have required an energy conversion to supply energy to(in the case of heating) or remove energy from (in the case of cooling)the air in the room. In the former case, typically a radiator elementhas been used to increase the total energy of the gaseous system of theroom to be heated by conversion of energy from, say, electrical energy.In the latter case, typically an air conditioner unit has been used todecrease the total energy of the gaseous system by converting heatenergy of the gaseous system into heat energy of a refrigerant (and thennormally reconverting the heat energy of the refrigerant into heatenergy of the atmosphere outside the room to be cooled). Such energyconversions are naturally less than fully efficient withthe result thatconsiderably more energy must be supplied to heat or cool the room thanis actually added to or extracted from the gaseous system. In addition,particularly in the case of i an air conditioner, the equipment foraccomplishing the energy conversion is relatively complex andcostly toproduce and install.

SUMMARY OF THE INVENTION It is anobject of the present invention toprovide both method and apparatus for heating and cooling a place ofhuman habitation which is more efficient and less costly in operationandinstallationthan the methods and apparatus of the prior art.

The present invention resides in the concept of directly changing theentropy rather than the total energy of the gaseous system so that noenergy conversion is required in the heating or cooling process. Thisconcept is effected in accordance with the present invention byseparating a quantity of gas into two individual component gases; afirst component gas containing molecules of the original gas which arerelatively fast and a second component gas containing molecules of theoriginal gas which are relatively slow. Although energy will be requiredto accomplish this separation, (i.e. to change the entropy) the methodand apparatus for accomplishing the method will function much moreefficiently than the heating and cooling methods and apparatus of theprior art since no internalenergy must be supplied to, or removed from,the gas.

The method and apparatus of the present invention can be realized by amolecular filter" that functions to pass molecules of a gas having highvelocities in preference to molecules having slow velocities, or viceversa. The molecules passed by the molecular filter form one of the twocomponent gases, while the molecules that remain (that are not passed)form the other. One such molecular filter, which forms the preferredembodiment of the present invention, will be described below.

As used herein, the term filter is intended to denote a strainer orsieve-like device, i.e., a device having a single input and output,which permits mass or energy of a particular type to pass from the inputto the output in preference to mass or energy of another type. Inaddition, a filter, in its ideal sense, is a passive device; i.e., adevice containing no moving parts or active elements which would becapable of operating on, varying or changing the mass or energy passedfrom the input to the output.

By way of explanation, it may be useful to consider an electricalband-pass filter as an example of a device for filtering energy. As iswell known, a band-pass filter is comprised of one or more inductors andcapacitors arranged in series, parallel, or both series and parallel.This filter is thus a two terminal device (single inputsingle output)comprised entirely of passive elements. It functions to pass electricalenergy of a particular frequency or range of frequencies from the inputto the output andto block the passage of electrical energy outside theband-pass range. In an ideal electrical filter there is no addition to(active elements) nor loss of (resistive elements) total energy. Ofcourse, in practice some losses are experienced in the inductors andcapacitors due to the resistance of those elements.

Thus, more specifically, the molecular filter referred to in the presentapplication is also a two terminal passive device. It functions topermit the passage of mass (gas) of a particular type from the input tothe output without changing or otherwise affecting the mass (gas). Forthe purposes of the present invention the only requirement of themolecular filter is that it be operative to selectively pass moleculesof a gas having a statistical distribution of velocities that isdifferent from the statistical distribution of molecular velocities inthe original gas to which one side thereof is exposed. Such a molecularfilter will allow the gas of the gaseous system to separate by molecularmotion into two component gases which are respectively hotter and colderthan the original gas; that is, by separating the original gas intocomponent gases having, respectively, a higher and a lower statisticaldistribution of molecular velocities than the statistical distributionof molecular velocities of the original gas.

- A molecular filter which is capable of preferentially passing highervelocity molecules may be formed by a wall having a plurality of holesor apertures therethrough. If a gas pump is provided for evacuating theregion on one side of the wall,.and a quantity of gas is disposed on theother side of the wall at a pressure that is greater than the pressurein the evacuated region, the molecules of this gas will continuouslypass through the apertures into the evacuated region. Although some ofthe molecules in the evacuated region will return through the aperturesto join the original gas on the other side of the wall, most will beremoved by the gas pump. Since, as will be shown below, the moleculeswhich pass through the apertures into the evacuated region will havehigher speeds, on the-average, than the molecules of the originalquantity of gas:

1. these molecules which are removed from the evacuated region by thegas pump will form a gas which is warmer than the original; and

2. the molecules which are left behind on the other side of the wallwill form a gas which is cooler than the original gas.

fast molecules have a statistically greater chance of 5 passing througha hole in a wall than do slow molecules. Although this fact comes intoplay whenever molecules pass through a small orifice, no heating orcooling effect can normally be observed, since, when the pressures onboth sides of the wall are the same, 10

and v are coordinates of velocity, is given by the so- 20 calledMaxwell-Boltzmann distribution:

m1 .v'.v*; =A w m B in this equation is given by llkT (where k is theBoltzmann constant and T the absolute temperature),

6 is the energy and A is a constant determined by the requirement that:

If fd x d V= N,

the total number of molecules. Solving this equation gives:

A N/V (mB/Zrr) where m is the mass of an individual molecule and V isthe total volume of the gas.

To calculate the distribution of velocities of mole- 40 l cules whichpass through an orifice, it is convenient to change the coordinates,making the center of the orifice the origin. Reference is made to FIG. 1of the drawing which shows, in cross section, a wall I having an orifice2 of area dS. The molecules incident on the orifice have a velocityvector 4 which makes an angle 0 with the normal to the orifice. Fromequation (1 the number of molecules that have a speed c (v, +v,, +v,)"""and whose velocity vector makes an angle 0 with the given axis, is

f(C,9) 2 'rr A e meg/2 c sin 0 d0 dc.

The number of such molecules that will pass through the orifice 2(assuming spatial homogeneity) in the time dt is given by:

d8 0 cos 0 dt f(c,0) I

so that, for all 0 the velocity distribution of thesemole- I culesbecomes:

If thefunction (3) is integrated over the same range of 0, it becomes 1This function, the well-known Maxwell-Boltzmann distribution ofmolecular velocities, is shown as the curve 6 in FIG. 2. As may be seenfrom thefigure, very few molecules of the ideal gas move with slowspeeds and very few with high speeds. Most of the molecules are groupedaround the maximum of the curve or the most probable speed. Because ofthe nonsymmetrical shape of the curve, the average speed is slightlylarger than the most probable and the root mean square speed is somewhatlarger than either the most probable or the average speed.

As has been proven above, the molecules which emerge through the orificedo not exhibit this distribution. Their velocities are given, rather, bythe function (5) which is (constant 0) times the function (6). Thisfunction is illustrated by the curve 5 in FIG. 2 which shows that themaximum speed, the average speed as well .as the root mean square speedwill be higher than that of the molecules of the original gas. Ofcourse, the molecules that pass through the orifice will also bedescribable by-the Maxwell-Boltzmann (ideal gas) function when the gaswhich they form reaches equilibrium, but since their velocities arehigher, their absolute temperature T will then be higher. Since thetotal energy of the gaseous system must remain constant, absent theintroduction .or withdrawal of heat, the gas which is formed of themolecules that emerge through the ori fice will be warmer, and the gasformed of the molecules that remain will be cooler than the gas whichwas originally placed on the right side of the wall 1 in FIG.

It should be noted that the theory upon which the present invention isbased assumes the presence of true molecular flow. If the orifice ismade too large, the gas will rush through it to the evacuated side ofthe wall causing turbulance (molecular collisions) that disturb theMaxwell-Boltzman equilibrium. However, the theory places no limits onthe number of orifices which can be provided in a wall per unit area.Any limitations on the size of each orifice can therefore be compensatedfor by providing large numbers of orifices closely adjacent to eachother.

It is preferable if the orifices be made with a diameter in the order ofmagnitude of the mean free path L, the average distance betweencollisions, of the molecules of the gas, However, at standard conditionsthis mean free path is extremely small:

L 3 10 Cm,

or a distance slightly smaller than the wavelength of light in thevisible spectrum. 7

Means should be provided, therefore, to make the holes simply as small,and as numerous as possible. This may be done, for example, by placing athin foil in the path of an electric discharge. The discharge, which isnot homogeneous, will penetrate the foil at a large number of randomlyselected points, producing the orifices as desired.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of awall having an orifice of elemental area.

FIG. 2 is a graph of molecular distributions of velocities whichillustrate the operation of the present invention.

FIG. 3 is a schematic diagram of the apparatus according to the presentinvention.

FIG. 4 is a representational diagram of the preferred embodiment of theapparatus shown in FIG. 3,

FIG. 5 is a representational diagram of apparatus, constructed accordingto the preferred embodiment of the present invention, for continuouslyseparating a gas into warmer and cooler gases.

FIG. 6 is a representational diagram of apparatus, constructed accordingto a preferred embodiment of the present invention, for cooling a room.

FIGS. 7a and 7b are side and top cross-sectional views, respectively, ofapparatus, constructed according to a further preferred embodiment ofthe present invention, for cooling a room.

DESCRIPTION OF THEPREFERRED EMBODIMENTS Turning now to the drawings,FIG. 3 schematically illustrates the general nature of apparatus,according to the present invention, for continuously separating a gasinto a warmer component gas and a cooler component gas.

The gas enters the system through the line 7 with the aid, if necessary,of a gas pump 8. The gas is then directed through the line 9 to themolecular filter system, according to the present invention, generallydesignated by the dashed lines. Part of the gas will be passed by thefilter 11 and drawn by the gas pump 12 to the outlet 13. The remaininggas will simply be ejected through the outlet 10. The filter 11 can beoperative either to selectively pass molecules of the gas having astatistical distribution of velocities that is greater than thestatistical distribution of velocities of the gas in the line 9, or vice.versa.

A molecular filter system having the former properties is shown,schematically, in FIG. 4. This filter system operates according to thetheory of selection described in the Summary of the Invention, above.The original gas is introduced into the tube 14 and directed against thescreen 16. This screen is in reality a thin foil containing largenumbers of small apertures. The molecules that pass through theapertures are drawn off by the gas pump, indicated by the fan 17, andpassed out the outlet tube 18. The molecules that do not manage to passthrough the screen 16 are passed out the outlet tube 15. As has beenexplained above, the gas ejected through the tube 18 will be warmerthan, and the gas ejected through the tube will be cooler than theoriginal gas that entered the tube 14.

FIGS. 5 and 6 illustrate two practical forms which the molecular filtersystem embodiment of FIG. 4 can take. The system shown in FIG. 5 isoperative to separate large amounts of gas into warmer and cooler gases,respectively, and the system-shown in FIG. 6 is operative to cool aroom.

The apparatus of FIG. 5 includes an inlet tube 20, a filter tube 24 andan outlet tube 22. The region 23 surrounding the filter tube isconnected to a second outlet tube 21. Air'is drawn through the filtertube 24 and is exhausted from the region 23 by means of two gas pumps 19and 19', respectively.

This apparatus operates in a manner identical to the molecular filtersystem embodiment of FIG. 4. In this case, however, the incoming gas iscaused to flow against numerous surfaces of the filter tube so that alarge proportion of this gas will pass into the evacuated region 23 andbe exhausted by the pump 19. In other words, the filter tube is providedwith sufficient screen" or aperture-filled surfaces to cause the desireddegree of separation of the incoming gas.

FIG. 6 shows a plan view of a room 25 provided with false walls 27containing a plurality of apertures. The region behind the walls isevacuated by a gas pump 28 which discharges the exhaust gases into theatmosphere 29. The room 25 is also provided with a door 26 and a solidwall 30.

The false walls 27 act to continuously filter through the fast moleculesof the gas in the room. Although the warm gas which is removed iscontinuously replenished by the outside air passing in through thedoorway, the room will be ,cooled since the gases removed will be warmerthan the replenishing gases. The apparatus shown in FIG. 6 thus acts asa type of air conditioner to circulate and cool the air in the room.

Although the system in FIG. 6 is illustrated as having false wallsspaced a short distance away from the true walls of the room, it is morepractical to provide the room with a false ceiling instead. If a falseceiling is constructed as the molecular filter there is less danger ofdamage to the filter and the filter will be effective to receive andwithdraw the warmer air in the room as it rises.

Conveniently, the ceiling filter system can be constructed as part ofthe false ceiling which is already commonly used to hide ventilationpipes, wiring, etc., in modern buildings. It is only necessary toreplace the usual acoustic tiles with tiles having the appropriate apertures and install a blower of sufficient capacity to establish apartial vacuum above the tiles. The "filt'er tiles can preferably beconstructed in a manner similar to the acoustic tiles in present use,but provided on their upper side with a thin foil containing aperturesof appropriately small size. If the body of the tile is madesufficiently porous, the gas molecules will diffuse through it and thenbe filtered through the apertures of the foil.

A false ceiling of the above-described type is illustrated in FIG. 7a.This figure shows a room 31 sur rounded by vertical walls 32 and ahorizontal ceiling 33. The ceiling is formed by a molecular filter whichis capable of selectively passing molecules of air which havestatistical distribution of velocities which is greater, or lesser, thanthe statistical distribution of velocities of the molecules that impingethereon. The space 34 above the ceiling 33 contains only braces 35 forholding the ceiling 33 and can be evacuated or pressurized by an airpump36.

If a molecular filter is chosen which selectively passes air having ahigher temperature than the air impinging thereon, the room may becooled by evacuating the space 34 or may be heated by pressurizing thespace 34 with respect to the room 31. If a molecular filter is chosenwhich selectively passes air having a lower temperature than the airimpinging thereon, the room may be cooled by pressurizing the space 34or may be heated by evacuating the space 34 with respect to theequilibrium established by the heating and cooling device and methodaccording to the present invention, the air in the doorway region may beheated or cooled, as desired, by a conventional heating or coolingdevice. This may be accomplished,.in the manner shown in FIG. 7b bymeans of a double door arrangement and an airstream 37 passed throughthe region between the doors by airpumps 38 and 39. Prior to insertioninto the region between the doors, the air is heated or cooled, as'desired, by a conventional heating or cooling device 40.

It should be emphasized that the conventional heating or cooling device40 does not replace the function of the molecular filter 33, but merelyserves to heat or cool the air which enters through the doors fromoutside the building. Depending upon the size of the building and thesize and frequency of use of the doorway or doorways, the conventionalheating or cooling device should provide only a small fraction of thetotal effective heating or cooling in the building.

It will be understood that the above description of the presentinvention is susceptible to various modifications, changes andadaptations. Although an apertured foil has been described herein as thepreferred embodiment of the molecular filter according to the presentinvention, it will be appreciated that various othertemperature-selective filters may be provided as well. For example, asimple gauze filter (made of cotton, fiberglass, or other gauzematerial) or some other specially fabricated semi-permeable membrane maybe used as the molecular filter for selectively passing molecules of agas which have a statistical distribution of molecular velocities thatis different from the statistical distribution of molecular velocitiesof the gas which impinges on one side thereof.

Accordingly, it is intended that the scope of the present invention belimited only by the following claims.

I claim:

1. In a human habitation having enclosing surfaces includingsubstantially vertical wall surfaces and a substantially horizontalceiling surface, the improvement wherein at least one of the enclosingsurfaces is formed, at least in part, by a molecular filter forselectively passing air of a different temperature than the airimpinging on one side thereof and wherein means are provided forestablishing a pressure differential across said molecular filter,thereby to change the temperature in the habitation.

2. The improvement defined in claim 1, wherein said ceiling surface isformed, at least in part, by said molecular filter.

3. The improvement defined in claim 1, wherein substantially all of saidceiling surface is formed by said molecular filter.

4. The improvement defined in claim 1, wherein said molecular filter isan apertured partition.

5. The improvementdefined in claim 2, wherein said means forestablishing a pressure differential include means for withdrawing airfrom the region above said ceiling and discharging the air withdrawnoutside the habitation.

6. The improvement defined in claim 1, wherein the temperature withinthe habitation is increased and means are provided for heating air whichenters the habi-tation through doorways.

7. The improvement defined in claim 1, wherein the temperature withinthe habitation is decreased and means are provided for cooling air whichenters the habitation through doorways.

1. In a human habitation having enclosing surfaces includingsubstantially vertical wall surfaces and a substantially horizontalceiling surface, the improvement wherein at least one of the enclosingsurfaces is formed, at least in part, by a molecular filter forselectively passing air of a different temperature than the airimpinging on one side thereof and wherein means are provided forestablishing a pressure differential across said molecular filter,thereby to change the temperature in the habitation.
 2. The improvementdefined in claim 1, wherein said ceiling surface is formed, at least inpart, by said molecular filter.
 3. The improvement defined in claim 1,wherein substantially all of said ceiling surface is formed by saidmolecular filter.
 4. The improvement defined in claim 1, wherein saidmolecular filter is an apertured partition.
 5. The improvement definedin claim 2, wherein said means for establishing a pressure differentialinclude means for withdrawing air from the region above said ceiling anddischarging the air withdrawn outside the habitation.
 6. The improvementdefined in claim 1, wherein the temperature within the habitation isincreased and means are provided for heating air which enters thehabi-tation through doorways.
 7. The improvement defined in claim 1,wherein the temperature within the habitation is decreased aNd means areprovided for cooling air which enters the habitation through doorways.